I thought I would pas this along. I got it from my son in law (who is a top Mercedes tech.
Anyway, my 1994 Chrysler has not been running as well as it could be. When I would go up a hill in overdrive (on the freeway for instance). If the rpm's were low, it felt like it would miss rather than downshift. So, I started running mid grade and sometimes supreme gas. And the problem went away.
I asked my son in law about that. He said that they have been testing gas samples around the area and found that , in some cases, the gas was 25% ethanol). (its supposed to be 10% or less). Not only will the high ethanol content make your car run bad, it will cause damage to the engine. He says they found that Chevron seems to be the best at keeping the octane under 10%. Its not the fault of the gas station, its the refinery trying to make better profits.
I don't know if it is the same in your area. But this is what it seems like it is in Seattle
TRat
Anyway, my 1994 Chrysler has not been running as well as it could be. When I would go up a hill in overdrive (on the freeway for instance). If the rpm's were low, it felt like it would miss rather than downshift. So, I started running mid grade and sometimes supreme gas. And the problem went away.
I asked my son in law about that. He said that they have been testing gas samples around the area and found that , in some cases, the gas was 25% ethanol). (its supposed to be 10% or less). Not only will the high ethanol content make your car run bad, it will cause damage to the engine. He says they found that Chevron seems to be the best at keeping the octane under 10%. Its not the fault of the gas station, its the refinery trying to make better profits.
I don't know if it is the same in your area. But this is what it seems like it is in Seattle
TRat